Depending upon the method of their production, olefin feedstocks may comprise a variety of impurities which have a negative impact upon the catalysts later contacted by the olefin feedstock. Impurities found in olefins that are produced by oligomerization of ethylene units can include phosphorous-containing impurities, including but not necessarily limited to organophosphines and organophosphine oxides. These phosphorous-containing compounds are largely removed from many olefin streams during the process of distillation to separate various “cuts” of olefins. Unfortunately, the organophosphines and organophosphine oxides found in C14-C18 streams tend to co-distill with the C14-C18 olefins in the product, making it difficult, if not impossible to remove these phosphine impurities by simple distillation.
C6-C36 olefins have utility in the fields of paper and pulp processing, drilling fluids, and machine or metal working oils. Alcohols of such olefins have commercial importance in a variety of applications, including detergents, soaps, surfactants, and freeze point depressants in lubricating oils. These alcohols are produced by a number of commercial processes, such as by oxo or hydroformylation of long chain olefins. In many of these applications, the olefin feedstocks are treated using acid catalysts.
Unfortunately, any basic phosphorus-containing compounds in these olefin feedstocks will negatively affect acid catalysts. The phosphorous-containing moieties that are basic in nature and will neutralize the active acid sites of the catalyst, which lowers catalyst activity and performance. The organophosphine moieties may even cause the olefins to oligomerize into undesirable forms.
Dienes are another impurity that negatively impact certain catalysts, in particular, hydroformylation catalysts comprising noble metals, such as palladium. Methods are needed to reduce the phosphorous-content, and the diene content, if desired, of olefin feedstocks.